Field of the Invention
The present invention relates to a printing apparatus and a control method.
Description of the Related Art
In a printing apparatus represented by an inkjet printing apparatus, the conveyance accuracy of a print medium such as paper influences the image quality. To improve the conveyance accuracy of a print medium, there has been proposed a technique of controlling driving of a conveyance roller by detecting the rotation amount of the conveyance roller. Japanese Patent Laid-Open No. 2013-78908 discloses a printing apparatus that detects the rotation amount of a conveyance roller using a rotary encoder. In the printing apparatus of Japanese Patent Laid-Open No. 2013-78908, the code wheel of the rotary encoder is provided coaxially with the conveyance roller. The code wheel can also be provided on, for example, a motor that drives the conveyance roller or a gear shaft between the motor and the conveyance roller. However, when the code wheel is provided coaxially with the conveyance roller, as in Japanese Patent Laid-Open No. 2013-78908, the apparatus is hardly affected by the backlash of the gear, resulting in advantage in the detection accuracy of the rotation amount.
When the code wheel is provided coaxially with the conveyance roller, the code wheel may be located on the moving path of a carriage with a printhead. To avoid the interference between the carriage and the code wheel, the code wheel is disposed at a position outside the moving range of the carriage. The larger the width of the carriage is, the farther outside the code wheel needs to be disposed. It is therefore difficult to reduce the device width of the printing apparatus (the width of the conveyance roller in the axial direction).